Generally, an liquid crystal display (LCD) mainly includes a transmissive type LCD, a reflective type LCD, and a semi-transmissive/semi-reflective type LCD. The transmissive type LCD has a backlight module, and the light source of the backlight module may be cold cathode fluorescent lamps (CCFLs), hot cathode fluorescent lamp (HCFLs), light emitting diodes (LEDs), or electro luminescent (EL) devices. Currently, the CCFL is widely used in most LCDs.
The light leakage of LCDs easily occurs in a dark-state having a low gray level. Further, because the LCD panel size is rapidly growing and the LCD panel is widely used in television sets, it is necessary to increase the viewing angle of LCD panels. However, the problem of light leakage associated with viewing angles should be strictly controlled. In addition, the backlight luminance is required to be adjusted dynamically because the dynamic contrast ratio of the LCD panel has to be increased to improve the display quality. However, conventionally, the above-mentioned problem is generally ignored when adjusting the luminance of the backlight because only the light in the environment is taken into account presently. Therefore, when employing a conventionally adjusting method, glimmer occurs easily in LCD panels. The luminance of LCD panels is not uniform, thereby degrading the display quality of LCD.
Consequently, there is a need to develop an adjusting system to improve the display quality of LCDs.